A mini-module is a module with small size and low output power. Currently, wire bonding technology is widely used in mini-module packages. One drawback is that due to the relatively long wire connection, the wire resistance is large, causing power loss and low efficiency. This limits the ability to carry high current. Additionally, the bonding wire is thin, and this produces a parasitic inductance, which can cause a resonant ringing during switching. The resonant ringing causes an additional loss in the circuit and generates electromagnetic interference (EMI) noise. Furthermore, wire bonding technology can only dissipate the heat produced by the mini-module from the bottom side, so its cooling capability is limited. As the load current becomes higher, wire bonding technology is not optimum because of power loss and limited heat dissipation ability.
To reduce the EMI noise, most prior-art methods focus on improving the underlying electrical circuitry, which generally makes the circuitry more complicated and increases cost. Further, these prior-art methods often sacrifice the efficiency of the circuitry.